Boiler system for both heating and hot water

ABSTRACT

The objective of the present invention is to provide a boiler system for bath heating and hot water that is capable of performing heating and hot water preheating by using a single circulation pump for both without the need to separately include a circulation pump for heating and a circulation pump for hot water preheating. In order to achieve the above objective, the present invention provides a boiler system for both heating and hot water, comprising: a heat exchanging unit; a heating water channel connected between the heat exchanging unit and a place to be heated; a tap water supply pipe for supplying tap water to the heat exchanging unit; a hot water supply pipe for supplying hot water to a place requiring hot water from the heat exchanging unit; a hot water recirculation channel connected to the hot water supply pipe at a first branch point branched from one side of the heating water channel; a hot water bypass channel connected from the second branch point branched from the other side of the heating water channel to the tap water supply pipe; and a circulation pump disposed between the first branch point and the second branch point.

TECHNICAL FIELD

The present invention relates to a boiler system for both heating andhot water, and more particularly, to a boiler system for both heatingand hot water, in which a conventional circulation pump is usable forboth heating and preheating of hot water without additionally installinga separate hot water circulation pump for preheating and circulating hotwater.

BACKGROUND ART

In general, boilers for both heating and hot water are devices thatcombust oil or a gas as fuel, heat water using heat generated in such acombustion process, and perform heating by circulating the heated wateralong a heating pipe or supply hot water using the heated water for aheat exchange with the hot water.

As an example of the related arts related to the boilers for bothheating and hot water, FIG. 1 illustrates a hot water supply device fora gas boiler disclosed in Korean Utility Model Registration No.20-0147551. The hot water supply device for a gas boiler shown in FIG. 1has a configuration in which a circulation pump 17 is installed on aheating water return pipe to circulate and supply heating water, asecond circulation pump 19 is installed on a portion of a tap watersupply pipe 9, and a hot water return pipe 9 a is installed to allow thetap water supply pipe 9 and a hot water supply pipe 11 to communicatewith each other, whereby when a hot water temperature measured by atemperature sensor 13 does not reach a hot water temperature set by auser, a boiler is operated in a hot water mode to increase a temperatureof hot water stored in the hot water return pipe 9 a to the set hotwater temperature.

According to such a configuration, the hot water stored in the hot waterreturn pipe 9 a may be preheated, thereby immediately supplying the hotwater to the user without a waiting time for the initial use of the hotwater.

However, in such a conventional hot water supply device, the circulationpump 17 for circulating the heating water and the second circulationpump 19 for preheating and circulating the hot water should beseparately installed, thereby resulting in an increase in purchase costof a pump and a reduction in ease of installation.

DISCLOSURE Technical Problem

The present invention is directed to a boiler system for both heatingand hot water capable of performing heating and preheating hot waterusing one pump for both heating and hot water without separatelyproviding a circulation pump for heating and a circulation pump forpreheating of hot water.

Technical Solution

According to an embodiment of the present invention, a boiler system forboth heating and hot water includes a heat exchange unit, a heatingwater channel connected between the heat exchange unit and a heatingdestination, a tap water supply pipe through which tap water is suppliedto the heat exchange unit, a hot water supply pipe through which heatingwater is supplied from the heat exchange unit to a hot waterdestination, a hot water recirculation channel connected to the hotwater supply pipe at a first branch point at which the hot waterrecirculation channel is branched from one side of the heating waterchannel, a hot water bypass channel connected to the tap water supplypipe at a second branch point at which the hot water bypass channel isbranched from the other side of the heating water channel, and acirculation pump disposed between the first branch point and the secondbranch point.

In an embodiment, the heat exchange unit may include a hot water storagetype heat exchanger configured to store the heating water supplied tothe heating destination therein and heat the heating water using a heatsource.

In another embodiment, the heat exchange unit may include a main heatexchanger configured to heat the heating water supplied for heating orsupplied for exchanging heat by using combustion heat and a hot waterheat exchanger configured to generate the hot water through a heatexchange between the heating water heated in the main heat exchanger andtap water.

The heating water channel may be connected between the main heatexchanger and the heating destination, and the tap water supply pipe andthe hot water supply pipe may be connected to the hot water heatexchanger.

In an embodiment, a first three-way valve may be provided at the firstbranch point, and a second three-way valve may be provided at the secondbranch point.

In another embodiment, a first three-way valve may be provided at thefirst branch point, and a check valve may be provided in the hot waterbypass channel to restrict a flow path so that preheated hot water flowsin only one direction toward the tap water supply pipe.

The heating water channel between the first branch point and the secondbranch point may be used as a common channel through which the heatingwater and preheated hot water selectively flow.

When a hot water preheating function is selected in a room controller,the circulation pump may be operated for a certain time such that thehot water preheating function is operated.

When a hot water function is selected in the room controller during theoperation of the hot water preheating function, the circulation pump maybe additionally operated for the certain time such that the hot waterpreheating function is operated.

When hot water is used in the hot water destination during the operationof the hot water preheating function, the operation of the circulationpump may be stopped, and the hot water supply function may be operated.

Advantageous Effects

According to a boiler system for both heating and hot water according tothe present invention, a circulation pump is installed on a heatingwater return pipe, a hot water recirculation pipe and a hot water bypasspipe are connected to both sides of the circulation pump of the heatingwater return pipe, a first three-way valve is installed at a branchpoint of the heating water return pipe and the hot water recirculationpipe, and a heating water or hot water circulation flow path is formedthrough a flow path conversion of the first three-way valve, and thusheating and preheating of hot water can be performed using onecirculation pump for both of heating and preheating, thereby reducingpurchase costs of a circulation pump and improving ease of installation.

In addition, a second three-way valve is installed at a branch point ofthe heating water return pipe and the hot water bypass pipe to form aflow path of heating water or hot water through a flow path conversion,or a check valve is installed in a flow path of the hot water bypasspipe to restrict the flow path such that preheated hot water passingthrough the hot water bypass pipe flows in one only direction toward atap water bypass pipe, thereby preventing a backflow phenomenon of tapwater to allow hot water to be smoothly preheated and circulated.

Furthermore, the present invention may be universally applied to varioustypes of boilers, such as gas boilers, in addition to hot water storagetype boilers without limitation.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating a configuration of a hot water supplydevice for a gas boiler according to the related art.

FIG. 2 is a view illustrating a flow path of heating water during aheating operation in a boiler system for both heating and hot wateraccording to a first embodiment of the present invention.

FIG. 3 is a view illustrating a flow path of hot water during preheatingof hot water in the boiler system for both heating and hot wateraccording to the first embodiment of the present invention.

FIG. 4 is a view illustrating flow paths of hot water and tap waterduring the initial use of the hot water in the boiler system for bothheating and hot water according to the first embodiment of the presentinvention.

FIG. 5 is a view illustrating a flow path of heating water during aheating operation in a boiler system for both heating and hot wateraccording to a second embodiment of the present invention.

FIG. 6 is a view illustrating a flow path of hot water during preheatingof the hot water in the boiler system for both heating and hot wateraccording to the second embodiment of the present invention.

FIG. 7 is a view illustrating flow paths of hot water and tap waterduring the initial use of the hot water in the boiler system for bothheating and hot water according to the second embodiment of the presentinvention.

FIG. 8 is a view illustrating a flow path of heating water during aheating operation in a boiler system for both heating and hot wateraccording to a third embodiment of the present invention.

FIG. 9 is a view illustrating a flow path of heating water duringpreheating of hot water in a boiler system for both heating and hotwater according to the third embodiment of the present invention.

FIG. 10 is a view illustrating a flow path of hot water duringpreheating of the hot water in the boiler system for both heating andhot water according to the third embodiment of the present invention.

FIG. 11 is a view illustrating flow paths of hot water and tap waterduring the initial use of the hot water in the boiler system for bothheating and hot water according to the third embodiment of the presentinvention.

FIG. 12 is a view illustrating a flow path of heating water during aheating operation in a boiler system for both heating and hot wateraccording to a fourth embodiment of the present invention.

FIG. 13 is a view illustrating a flow path of heating water whenpreheating of hot water in the boiler system for both heating and hotwater according to the fourth embodiment of the present invention.

FIG. 14 is a view illustrating a flow path of hot water duringpreheating of the hot water in the boiler system for both heating andhot water according to the fourth embodiment of the present invention.

FIG. 15 is a view illustrating flow paths of hot water and tap waterduring the initial use of the hot water in the boiler system for bothheating and hot water according to the fourth embodiment of the presentinvention.

FIG. 16 is a control block diagram of a boiler system for both heatingand hot water according to the present invention.

Descriptions of Reference Numerals 1: gas valve 3: burner 5: heatexchanger 7: exhaust flue 9: tap water supply pipe 9a: hot water returnpipe 11: hot water supply pipe 13: temperature sensor 15: water tank 17:circulation pump 19: second circulation pump 21: flow valve V: three-wayvalve 100-1, 100-2: boiler system 101: heating water supply pipe 102:heating water return pipe 103: tap water pipe 104: tap water supply pipe105: hot water supply pipe 106: hot water bypass channel 107: hot waterrecirculation channel 110: hot water storage type heat exchanger 120:heating destination 130: hot water destination 140: circulation pump150: first three-way valve 160: second three-way valve 170: check valve200-1, 200-2: boiler system 201: heating water supply pipe 202: heatingwater return pipe 203: heating water bypass pipe 204: tap water pipe205: tap water supply pipe 206: hot water supply pipe 207: hot waterbypass channel 208: hot water recirculation channel 210: main heatexchanger 220: hot water heat exchanger 230: heating destination 240:hot water destination 250: three-way valve 260: circulation pump 270:first three-way valve 280: second three-way valve 290: check valve 300:room controller 310: heating button 320: water preheating button 330:hot water button 400: control unit B: burner F: air blower

BEST MODES OF THE INVENTION

Hereinafter, the configurations and operations of exemplary embodimentsof the present invention will be described in detail with reference tothe accompanying drawings. In the drawings, solid arrows refer to a flowpath of heating water, and hollow arrows refer to a flow path of hotwater or tap water.

Referring to FIGS. 2 to 4, a boiler system 100-1 for both heating andhot water according to a first embodiment of the present inventionincludes a hot water storage type heat exchanger 110 which storesheating water supplied to a heating destination 120, heats the heatingwater using a heat source (not shown), and generates hot water through aheat exchange between the heated heating water and tap water.

A heating water supply pipe 101 and a heating water return pipe 102 areconnected between the hot water storage type heat exchanger 110 and theheating destination 120 to form a heating water channel.

A tap water pipe 103 and a hot water supply pipe 105 are connected to ahot water destination 130.

A tap water supply pipe 104 is branched from the tap water pipe 103 andis connected to pass through the inside of the hot water storage typeheat exchanger 110. The tap water supply pipe 104 inside the hot waterstorage type heat exchanger 110 is connected to the hot water supplypipe 105. Tap water, which passes through the tap water supply pipe 104passing through the inside of the hot water storage type heat exchanger110, is heated through a heat exchange with the heated heating waterstored in the hot water storage type heat exchanger 110 and is generatedinto hot water to be supplied to the hot water supply pipe 105.

A circulation pump 140 is installed on the heating water return pipe 102to pump heating water or preheated hot water.

One end of a hot water bypass channel 106 is connected to the heatingwater return pipe 102 positioned at an outlet side of the circulationpump 140, and the other end of the hot water bypass channel 106 isconnected to the tap water supply pipe 104.

One end of a hot water recirculation channel 107 is connected to theheating water return pipe 102 positioned at an inlet side of thecirculation pump 140, and the other end of the hot water recirculationchannel 107 is connected to the hot water supply pipe 105.

A first three-way valve 150 configured to convert a flow path isprovided at a first branch point at which the heating water return pipe102 and the hot water recirculation channel 107 are connected. A secondthree-way valve 160 configured to convert a flow path is provided at asecond branch point at which the heating water return pipe 102 and thehot water bypass channel 106 are connected.

Referring to FIG. 2, during a heating operation, the circulation pump140 is operated, and the first three-way valve 150 forms flow paths suchthat a flow path toward the heating destination 120 and a flow pathtoward the circulation pump 140 are opened and a flow path toward thehot water recirculation channel 107 is closed. In addition, the secondthree-way valve 160 forms flow paths such that the flow path toward thecirculation pump 140 and a flow path toward the hot water storage typeheat exchanger 110 are opened and a flow path toward the hot waterbypass channel 106 is closed.

Thus, as indicated by arrows in FIG. 2, heating water heated in the hotwater storage type heat exchanger 110 is supplied to the heatingdestination 120 through the heating water supply pipe 101. In addition,the heating water, which transfers heat to the heating destination 120,is returned to the hot water storage type heat exchanger 110 through theheating water return pipe 102 and circulated.

Referring to FIG. 3, during preheating of hot water, the circulationpump 140 is operated, and the first three-way valve 150 forms flow pathssuch that the flow path toward the hot water recirculation channel 107and the flow path toward the circulation pump 140 are opened and theflow path toward the heating destination 120 is closed. In addition, thesecond three-way valve 160 forms flow paths such that the flow pathtoward the circulation pump 140 and the flow path toward the hot waterbypass channel 106 are opened and the flow path toward the hot waterstorage type heat exchanger 110 is closed.

Therefore, as indicated by arrows in FIG. 3, preheated hot water, whichis heated by absorbing heat of heating water in the hot water storagetype heat exchanger 110, is returned to the hot water storage type heatexchanger 110 via a hot water preheating circulation channel, in whichthe hot water supply pipe 105, the hot water recirculation channel 107,the first three-way valve 150, the circulation pump 140, the secondthree-way valve 160, and the hot water bypass channel 106 are connected,and circulated.

Referring to FIG. 4, when hot water is used in the hot water destination130 during preheating of the hot water, the circulation pump 140 isoperated for a set time, and thus, as shown by arrows in FIG. 4, thepreheated hot water is supplied to the hot water destination 130 by theoperation of the circulation pump 140. When the set time has elapsed,the operation of the circulation pump 140 is stopped.

After the preheated hot water present in the hot water preheatingcirculation channel is supplied to the hot water destination 130, tapwater introduced through the tap water pipe 103 is supplied into the hotwater storage type heat exchanger 110 through the tap water supply pipe104, is heated through a heat exchange with the heating water, and thenis supplied to the hot water destination 130 through the hot watersupply pipe 105.

As described above, since the preheated hot water remaining in the hotwater preheating circulation channel is supplied to a user for theinitial use of the hot water, water having a warm temperature desired bythe user may be immediately supplied.

Meanwhile, as shown in FIGS. 2 to 4, the heating water return pipe 102from the first branch point of the heating water return pipe 102 and thehot water recirculation channel 107 to the second branch point of theheating water return pipe 102 and the hot water bypass channel 106 isused as a common channel through which heating water and preheated hotwater selectively flow.

As described above, since heating water may be mixed into hot water in asection which is used for both of a channel for the heating water and achannel for the preheated hot water, in order to minimize a flow rate atwhich the heating water is mixed into the hot water, a distance betweenthe branch point of the heating water return pipe 102 and the hot waterrecirculation channel 107 and the branch point of the heating waterreturn pipe 102 and the hot water bypass channel 106 may be designed tobe minimized, which will be equally applied to the followingembodiments.

Hereinafter, the configurations and operations of a boiler system 100-2for both heating and hot water according to a second embodiment of thepresent invention will be described with reference to FIGS. 5 to 7, andthe same components as those of the above described first embodiment aredenoted by the same reference numerals and repetitive descriptionsthereof will be omitted.

The boiler system 100-2 for both heating and hot water according to thesecond embodiment of the present invention is different from that of thefirst embodiment in that a second three-way valve 160 is omitted and acheck valve 170 is further provided in a hot water bypass channel 106 toallow preheated hot water passing through the hot water bypass channel106 to flow in only one direction toward a tap water supply pipe 104 andrestrict a flow path such that the preheated hot water is blocked fromflowing in a direction opposite to the one direction, and othercomponents thereof may be the same as those of the first embodiment.

Referring to FIG. 5, during a heating operation, a circulation pump 140is operated, and a first three-way valve 150 forms flow paths such thata flow path toward a heating destination 120 and a flow path toward thecirculation pump 140 are opened and a flow path toward a hot waterrecirculation channel 107 is closed.

Thus, as indicated by arrows in FIG. 5, heating water heated in a hotwater storage type heat exchanger 110 is supplied to the heatingdestination 120 through a heating water supply pipe 101. In addition,the heating water, which transfers heat to the heating destination 120,is returned to the hot water storage type heat exchanger 110 through aheating water return pipe 102 and circulated.

In this case, since the first three-way valve 150 is in a state in whichthe flow path toward the hot water recirculation channel 107 is closed,heating water passing through the circulation pump 140 is prevented frombeing supplied to a channel in which the hot water bypass channel 106, ahot water supply pipe 105, and the hot water recirculation channel 107are connected.

Referring to FIG. 6, during preheating of hot water, the circulationpump 140 is operated, and the first three-way valve 150 forms flow pathssuch that the flow path toward the hot water recirculation channel 107and the flow path toward the circulation pump 140 are opened and theflow path toward the heating destination 120 is closed.

Therefore, as indicated by arrows in FIG. 6, preheated hot water, whichis heated by absorbing heat of heating water in the hot water storagetype heat exchanger 110, is returned to the hot water storage type heatexchanger 110 via a hot water preheating circulation channel, in whichthe hot water supply pipe 105, the hot water recirculation channel 107,the first three-way valve 150, the circulation pump 140, and the hotwater bypass channel 106 are connected, and circulated.

In this case, since the first three-way valve 150 is in a state in whichthe flow path toward the heating destination 120 is closed, preheatedhot water passing through the circulation pump 140 is prevented frombeing supplied to a channel in which the hot water storage type heatexchanger 110, the heating water supply pipe 101, and the heatingdestination 120 are connected.

In addition, a backflow phenomenon of tap water may be prevented by thecheck valve 170 installed on the hot water bypass channel 106, and thus,hot water may be smoothly preheated and circulated.

Referring to FIG. 7, when hot water is used in a hot water destination130 during preheating of the hot water, the circulation pump 140 isoperated for a set time, and thus, as shown by arrows, the preheated hotwater is supplied to the hot water destination 130 by the operation ofthe circulation pump 140. When the set time has elapsed, the operationof the circulation pump 140 is stopped.

After the preheated hot water present in the hot water preheatingcirculation channel is supplied to the hot water destination 130, asshown by arrows, tap water introduced through a tap water pipe 103 issupplied into the hot water storage type heat exchanger 110 through thetap water supply pipe 104, is heated through a heat exchange with theheating water, and then is supplied to the hot water destination 130through the hot water supply pipe 105.

The above-described first and second embodiments are embodiments of acase in which the present invention is applied to a hot water storagetype boiler system. Hereinafter, third and fourth embodiments of a casein which the present invention is applied to a gas boiler system will bedescribed.

Referring to FIGS. 8 to 11, a boiler system 200-1 for both heating andhot water according to the third embodiment of the present inventionincludes a main heat exchanger 210 which heats heating water suppliedfor heating or supplied for exchanging heat by using combustion heat anda hot water heat exchanger 220 which generates hot water by exchangingheat between the heated heating water, which is heated by the main heatexchanger 210, and tap water. Reference symbol “F” denotes an air blowerconfigured to supply combustion air, and reference symbol “B” denotes aburner configured to burn a mixture gas of combustion air and a gas.

A heating water supply pipe 201 and a heating water return pipe 202 areconnected between the main heat exchanger 210 and a heating destination230 to form a heating water channel.

A heating water bypass pipe 203 is connected to the heating water supplypipe 201 such that heating water supplied from the main heat exchanger210 flows toward the heating water return pipe 202 via the hot waterheat exchanger 220. A three-way valve 250 configured to selectivelyconvert a flow path of heating water toward the heating destination 230or the hot water heat exchanger 220 is provided at a branch point of theheating water supply pipe 201 and the heating water bypass pipe 203.

A tap water pipe 204 and a hot water supply pipe 206 are connected to ahot water destination 240.

A tap water supply pipe 205 is branched from the tap water pipe 204 andis connected to pass through the inside of the hot water heat exchanger220. The tap water supply pipe 205 inside the hot water heat exchanger220 is connected to the hot water supply pipe 206. Tap water, whichpasses through the tap water supply pipe 205 passing through the insideof the hot water heat exchanger 220, is heated through a heat exchangewith heating water passing through the inside of the heating waterbypass pipe 203 passing through the hot water heat exchanger 220 and issupplied to the hot water supply pipe 206.

A circulation pump 260 is installed on the heating water return pipe 202to pump heating water or preheated hot water.

One end of a hot water bypass channel 207 is branched and connected tothe heating water return pipe 202 positioned at an outlet side of thecirculation pump 260, and the other end of the hot water bypass channel207 is connected to the tap water supply pipe 205.

One end of a hot water recirculation channel 208 is branched andconnected to the heating water return pipe 202 positioned at an inletside of the circulation pump 260, and the other end of the hot waterrecirculation channel 208 is connected to the hot water supply pipe 206.

A first three-way valve 270 configured to convert a flow path isprovided at a first branch point at which the heating water return pipe202 and the hot water recirculation channel 208 are connected. A secondthree-way valve 280 configured to convert a flow path is provided at asecond branch point at which the heating water return pipe 202 and thehot water bypass channel 207 are connected.

Referring to FIG. 8, during a heating operation, the circulation pump260 is operated, and the first three-way valve 270 forms flow paths suchthat a flow path toward the heating destination 230 and a flow pathtoward the circulation pump 260 are opened and a flow path toward thehot water recirculation channel 208 is closed. In addition, the secondthree-way valve 280 forms flow paths such that the flow path toward thecirculation pump 260 and a flow path toward the main heat exchanger 210are opened and a flow path toward the hot water bypass channel 207 isclosed.

In addition, the three-way valve 250 forms flow paths such that the flowpath toward the heating destination 230 is opened and a flow path towardthe heating water bypass pipe 203 is closed.

Thus, as indicated by arrows in FIG. 8, heating water heated in the mainheat exchanger 210 is supplied to the heating destination 230 throughthe heating water supply pipe 201. In addition, the heating water, whichtransfers heat to the heating destination 230, is returned to the mainheat exchanger 210 through the heating water return pipe 202 andcirculated.

Referring to FIG. 9, during preheating of hot water, in order to storeheat in heating water in the hot water heat exchanger 220, the three-wayvalve 250 forms flow paths such that the flow path toward the heatingwater bypass pipe 203 is opened and the flow path toward the heatingdestination 230 is closed.

Thus, heating water heated in the main heat exchanger 210 passes throughthe hot water heat exchanger 220 via the heating water supply pipe 201and the heating water bypass pipe 203 and then is returned to the mainheat exchanger 210 through the heating water return pipe 202 andcirculated.

When heat is stored in the heating water in the hot water heat exchanger220, as shown in FIG. 10, the circulation pump 260 is operated topreheat hot water, and the first three-way valve 270 forms flow pathssuch that the flow path toward the hot water recirculation channel 208and the flow path toward the circulation pump 260 are opened and theflow path toward the heating destination 230 is closed. In addition, thesecond three-way valve 280 forms flow paths such that the flow pathtoward the circulation pump 260 and the flow path toward the hot waterbypass channel 207 are opened and the flow path toward the main heatexchanger 210 is closed.

Therefore, as indicated by arrows in FIG. 10, preheated hot water, whichis heated by absorbing heat of heating water in the hot water heatexchanger 220, is returned to the hot water heat exchanger 220 via a hotwater preheating circulation channel, in which the hot waterrecirculation channel 208, the first three-way valve 270, thecirculation pump 260, the second three-way valve 280, the hot waterbypass channel 207, and the tap water supply pipe 205 are connected, andcirculated.

During preheating of hot water, operations of FIGS. 9 and 10 may bealternately performed.

Referring to FIG. 11, when hot water is used in the hot waterdestination 240 during preheating of the hot water, the circulation pump260 is operated for a set time, and thus, as shown by arrows, thepreheated hot water is supplied to the hot water destination 240 by theoperation of the circulation pump 260. When the set time has elapsed,the operation of the circulation pump 260 is stopped.

After the preheated hot water present in the hot water preheatingcirculation channel is supplied to the hot water destination 240, asshown by arrows, tap water introduced through the tap water pipe 204 issupplied into the hot water heat exchanger 220 through the tap watersupply pipe 205, is heated through a heat exchange with the heatedheating water passing through the hot water heat exchanger 220 as shownand described with reference to FIG. 9, and then is supplied to the hotwater destination 240 through the hot water supply pipe 206.

As described above, since the preheated hot water remaining in the hotwater preheating circulation channel is supplied to a user for theinitial use of the hot water, water having a warm temperature desired bythe user may be immediately supplied.

Hereinafter, the configurations and operations of a boiler system 200-2for both heating and hot water according to the fourth embodiment of thepresent invention will be described with reference to FIGS. 12 to 15,and the same components as those of the above described third embodimentare denoted by the same reference numerals and repetitive descriptionsthereof will be omitted.

The boiler system 200-2 for both heating and hot water according to thefourth embodiment of the present invention is different from that of thethird embodiment in that a second three-way valve 280 is omitted and acheck valve 290 is further provided in a hot water bypass channel 207 toallow preheated hot water passing through the hot water bypass channel207 to flow in only one direction toward a tap water supply pipe 205 andrestrict a flow path such that the preheated hot water is blocked fromflowing in a direction opposite to the one direction, and othercomponents thereof may be the same as those of the third embodiment.

Referring to FIG. 12, during a heating operation, a circulation pump 260is operated, and a first three-way valve 270 forms flow paths such thata flow path toward a heating destination 230 and a flow path toward thecirculation pump 260 are opened and a flow path toward a hot waterrecirculation channel 208 is closed.

In addition, a three-way valve 250 forms flow paths such that the flowpath toward the heating destination 230 is opened and a flow path towarda heating water bypass pipe 203 is closed.

Thus, as indicated by arrows in FIG. 12, heating water heated in a mainheat exchanger 210 is supplied to the heating destination 230 through aheating water supply pipe 201. In addition, the heating water, whichtransfers heat to the heating destination 230, is returned to the mainheat exchanger 210 through a heating water return pipe 202 andcirculated.

In this case, since the first three-way valve 270 is in a state in whichthe flow path toward the hot water recirculation channel 208 is closed,heating water passing through the circulation pump 260 is prevented frombeing supplied to a channel connected in which the hot water bypasschannel 207, the tap water supply pipe 205, a hot water supply pipe 206,and a hot water recirculation channel 208 are connected.

Referring to FIG. 13, during preheating of hot water, in order to storeheat in heating water in a hot water heat exchanger 220, the three-wayvalve 250 forms flow paths such that the flow path toward the heatingwater bypass pipe 203 is opened and the flow path toward the heatingdestination 230 is closed.

Thus, heating water heated in the main heat exchanger 210 passes throughthe hot water heat exchanger 220 through the heating water supply pipe201 and the heating water bypass pipe 203 and then is returned to themain heat exchanger 210 through the heating water return pipe 202 andcirculated.

When heat is stored in the heating water in the hot water heat exchanger220, as shown in FIG. 14, the circulation pump 260 is operated, and thefirst three-way valve 270 forms flow paths such that the flow pathtoward the hot water recirculation channel 208 and the flow path towardthe circulation pump 260 are opened and the flow path toward the heatingdestination 230 is closed.

Therefore, as indicated by arrows in FIG. 14, preheated hot water, whichis heated by absorbing heat of heating water in the hot water heatexchanger 220, is returned to the hot water heat exchanger 220 via a hotwater preheating circulation channel, in which the hot waterrecirculation channel 208, the first three-way valve 270, thecirculation pump 260, the hot water bypass channel 207, and the tapwater supply pipe 205 are connected, and circulated.

In this case, since the first three-way valve 270 is in a state in whichthe flow path toward the heating destination 230 is closed, preheatedhot water passing through the circulation pump 260 is prevented frombeing supplied to a channel in which the main heat exchanger 210, theheating water supply pipe 201, and the heating destination 230 areconnected.

In addition, a backflow phenomenon of tap water may be prevented by thecheck valve 290 installed on the hot water bypass channel 207, and thus,hot water may be smoothly preheated and circulated.

During preheating of hot water, operations of FIGS. 13 and 14 may bealternately performed.

Referring to FIG. 15, when hot water is used in a hot water destination240 during preheating of the hot water, the circulation pump 260 isoperated for a set time, and thus, as shown by arrows, the preheated hotwater is supplied to the hot water destination 240 by the operation ofthe circulation pump 260. When the set time has elapsed, the operationof the circulation pump 260 is stopped.

After the preheated hot water present in the hot water preheatingcirculation channel is supplied to the hot water destination 240, asshown by arrows, tap water introduced through the tap water pipe 204 issupplied into the hot water heat exchanger 220 through the tap watersupply pipe 205, is heated through a heat exchange with the heatedheating water passing through the hot water heat exchanger 220 as shownand described with reference to FIG. 13, and then is supplied to the hotwater destination 240 through the hot water supply pipe 206.

FIG. 16 is a control block diagram of the boiler system for both heatingand hot water according to the present invention. A room controller 300may include a heating button 310 for allowing a user to operate aheating function, a water preheating button 320 for allowing the user tooperate a hot water preheating function, and a hot water button 330 forallowing the user to operate a hot water function.

When the user presses and selects one of the heating button 310, thewater preheating button 320, and the hot water button 330 provided inthe room controller 300, a selected signal is sent to a control unit400, and the control unit 400 controls operations of the circulationpump 140 or 260, the first three-way valve 150 or 270, and the secondthree-way valve 160 or 280 to perform a selected function.

When the user presses the water preheating button 320 to select the hotwater preheating function, the control unit 400 may perform a control tooperate the circulation pump 140 or 260 for a certain time (for example,60 seconds) such that the hot water preheating function is operated.

During the operation of the hot water preheating function, when the userpresses the hot water button 330 to select the hot water function, thecontrol unit 400 may perform a control to additionally operate thecirculation pump 140 or 260 for a certain time (for example, 60 seconds)such that the hot water preheating function is operated.

During the operation of the hot water preheating function, when hotwater is used in the hot water destination 130 or 240, the control unit400 may perform a control to stop the operation of the circulation pump140 or 260 such that hot water supplying function is continuouslyoperated. The control unit 400 may determine whether the hot water isused in the hot water destination 130 or 240 based on a signal sensed bya flow sensor (not shown) provided on the tap water pipe 103 or 204 tosense a flow of tap water.

On the other hand, in the present specification, it has been describedthat the circulation pump 140 or 260 transports a fluid in only onedirection, but the circulation pump 140 or 260 may be configured totransport the fluid in both directions. In this case, even when thearrangement order of the first and second branch points is reversed fromthat shown in the drawings, a hot water preheating function may beperformed.

In addition, the hot water recirculation channel 107 or 208 and the hotwater bypass channel 106 or 207 may be disposed inside the boiler or maybe disposed outside the boiler (in a piping of a house).

As described above, the present invention is not limited to thedescribed embodiments, and it should be construed that modifications canbe apparently devised by those skilled in the art without departing fromthe technical spirit of the present invention defined by the appendedclaims, and also such modifications will fall within the scope of thepresent invention.

1. A boiler system for both heating and hot water, comprising: a heatexchange unit; a heating water channel connected between the heatexchange unit and a heating destination; a tap water supply pipe throughwhich tap water is supplied to the heat exchange unit; a hot watersupply pipe through which heating is supplied from the heat exchangeunit to a hot water destination; a hot water recirculation channelconnected to the hot water supply pipe from a first branch point atwhich the hot water recirculation channel is branched from one side ofthe heating water channel; a hot water bypass channel connected to thetap water supply pipe at a second branch point at which the hot waterbypass channel is branched from the other side of the heating waterchannel; and a circulation pump disposed between the first branch pointand the second branch point.
 2. The boiler system of claim 1, whereinthe heat exchange unit includes a hot water storage type heat exchangerconfigured to store the heating water supplied to the heatingdestination therein and heat the heating water using a heat source. 3.The boiler system of claim 1, wherein the heat exchange unit includes amain heat exchanger configured to heat the heating water supplied forheating or supplied for exchanging heat by using combustion heat and ahot water heat exchanger configured to generate the hot water through aheat exchange between the heating water heated in the main heatexchanger and tap water.
 4. The boiler system of claim 3, wherein theheating water channel is connected between the main heat exchanger andthe heating destination, and the tap water supply pipe and the hot watersupply pipe are connected to the hot water heat exchanger.
 5. The boilersystem of claim 1, wherein a first three-way valve is provided at thefirst branch point, and a second three-way valve is provided at thesecond branch point.
 6. The boiler system of claim 1, wherein a firstthree-way valve is provided at the first branch point, and a check valveis provided in the hot water bypass channel to restrict a flow path suchthat preheated hot water flows in only one direction toward the tapwater supply pipe.
 7. The boiler system of claim 1, wherein the heatingwater channel between the first branch point and the second branch pointis used as a common channel through which the heating water andpreheated hot water selectively flow.
 8. The boiler system of claim 1,wherein, when a hot water preheating function is selected in a roomcontroller, the circulation pump is operated for a certain time so thatthe hot water preheating function is operated.
 9. The boiler system ofclaim 8, wherein, when a hot water function is selected in the roomcontroller during the operation of the hot water preheating function,the circulation pump is additionally operated for the certain time sothat the hot water preheating function is operated.
 10. The boilersystem of claim 9, wherein, when hot water is used in the hot waterdestination during the operation of the hot water preheating function,the operation of the circulation pump is stopped, and the hot watersupply function is operated.